title: Medical utilization and cost in patients with overlap syndrome of chronic obstructive pulmonary disease and asthma.
abstract: BACKGROUND
  Little information is available regarding medical utilization and cost in patients with overlap syndrome of chronic obstructive pulmonary disease (COPD) and asthma. The purpose of this study is to analyze medical utilization and cost in patients with overlap syndrome and to compare them to COPD patients without asthma.
  
  
  METHODS
  Using the 2009 Korean National Health Insurance (NHI) database, COPD patients were identified. Medical utilization and costs were also analyzed.
  
  
  RESULTS
  Of a total of 185,147 patients identified with COPD, 101,004 patients were classified with overlap syndrome of COPD and asthma and 84,143 patients with COPD without asthma. In 2009, the percentages of emergency room visits, admissions, and intensive care unit admissions were 14.6%, 30.5%, and 0.5%, respectively, in the patients with overlap syndrome group and 5.0%, 14.1%, and 0.2%, respectively, in the COPD patients without asthma group (p < 0.05 for all comparisons). The cost of medical utilization was 790 ± 71 US dollars per person and 3,373 ± 4,628 dollars per person for outpatient and inpatient services, respectively, in the patients with overlap syndrome and 413 ± 512 and 3,010 ± 5,013, respectively, in the COPD patients without asthma (p < 0.05 for all comparisons). Multiple linear regression showed that age, sex, overlap syndrome, hospitalization in the last year, low socioeconomic status, and type of hospital use were significant factors affecting medical utilization and cost.
  
  
  CONCLUSIONS
  In patients with overlap syndrome, both medical utilization and cost were higher than in COPD patients without asthma.
authors.affiliation: 1Department of Internal Medicine, Seoul St. Mary's Hospital, Catholic University of Korea , Seoul , Republic of Korea.
authors.forename: Chin Kook
authors.initials: CK
authors.lastname: Rhee
authors.forename: Hyoung Kyu
authors.initials: HK
authors.lastname: Yoon
authors.forename: Kwang Ha
authors.initials: KH
authors.lastname: Yoo
authors.forename: Young Sam
authors.initials: YS
authors.lastname: Kim
authors.forename: Sei Won
authors.initials: SW
authors.lastname: Lee
authors.forename: Yong Bum
authors.initials: YB
authors.lastname: Park
authors.forename: Jin Hwa
authors.initials: JH
authors.lastname: Lee
authors.forename: Yuri
authors.initials: Y
authors.lastname: Kim
authors.forename: Kyungjoo
authors.initials: K
authors.lastname: Kim
authors.forename: Jinhee
authors.initials: J
authors.lastname: Kim
authors.forename: Yeon Mok
authors.initials: YM
authors.lastname: Oh
authors.forename: Sang Do
authors.initials: SD
authors.lastname: Lee
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D001249:Asthma / Q000150:complications* / Q000191:economics* / Q000628:therapy; D016022:Case-Control Studies; D005260:Female; D017048:Health Care Costs / Q000706:statistics & numerical data*; D006296:Health Services / Q000191:economics / Q000706:statistics & numerical data*; D006760:Hospitalization / Q000191:economics / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D008875:Middle Aged; D029424:Pulmonary Disease, Chronic Obstructive / Q000150:complications* / Q000191:economics* / Q000628:therapy; D056910:Republic of Korea; D013577:Syndrome